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Commit b46882e4 authored by Borislav Petkov's avatar Borislav Petkov Committed by H. Peter Anvin
Browse files

x86, cpu: Add AMD TLB size detection 



Read I- and DTLB entries count from CPUID on AMD. Handle all the
different family-specific cases.

Signed-off-by: default avatarBorislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1344272439-29080-4-git-send-email-bp@amd64.org


Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 5b556332

arch/x86/kernel/cpu/amd.c

+54 −0
Original line number Diff line number Diff line
@@ -737,6 +737,59 @@ static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c, 
}

#endif



static void __cpuinit cpu_detect_tlb_amd(struct cpuinfo_x86 *c)

{

	u32 ebx, eax, ecx, edx;

	u16 mask = 0xfff;



	if (c->x86 < 0xf)

		return;



	if (c->extended_cpuid_level < 0x80000006)

		return;



	cpuid(0x80000006, &eax, &ebx, &ecx, &edx);



	tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;

	tlb_lli_4k[ENTRIES] = ebx & mask;



	/*

	 * K8 doesn't have 2M/4M entries in the L2 TLB so read out the L1 TLB

	 * characteristics from the CPUID function 0x80000005 instead.

	 */

	if (c->x86 == 0xf) {

		cpuid(0x80000005, &eax, &ebx, &ecx, &edx);

		mask = 0xff;

	}



	/* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */

	if (!((eax >> 16) & mask)) {

		u32 a, b, c, d;



		cpuid(0x80000005, &a, &b, &c, &d);

		tlb_lld_2m[ENTRIES] = (a >> 16) & 0xff;

	} else {

		tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;

	}



	/* a 4M entry uses two 2M entries */

	tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;



	/* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */

	if (!(eax & mask)) {

		/* Erratum 658 */

		if (c->x86 == 0x15 && c->x86_model <= 0x1f) {

			tlb_lli_2m[ENTRIES] = 1024;

		} else {

			cpuid(0x80000005, &eax, &ebx, &ecx, &edx);

			tlb_lli_2m[ENTRIES] = eax & 0xff;

		}

	} else

		tlb_lli_2m[ENTRIES] = eax & mask;



	tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;

}



static const struct cpu_dev __cpuinitconst amd_cpu_dev = {

	.c_vendor	= "AMD",

	.c_ident	= { "AuthenticAMD" },
@@ -756,6 +809,7 @@ static const struct cpu_dev __cpuinitconst amd_cpu_dev = { 
	.c_size_cache	= amd_size_cache,

#endif

	.c_early_init   = early_init_amd,

	.c_detect_tlb	= cpu_detect_tlb_amd,

	.c_bsp_init	= bsp_init_amd,

	.c_init		= init_amd,

	.c_x86_vendor	= X86_VENDOR_AMD,